Because Chase actually does something sort of similar (primarily mortgage lending), but they employ a ton of people to think all day about managing risk.
So I think people don't like the comparison, since the true difference is FTX did horse betting, while Chase does something much more rational.
To add to that: Chase tells you what they're doing. FTX told its customers it wouldn't lend it out, and then it did. Additionally, customer accounts at Chase are insured by FDIC up to $250k. Chase tells you they're going to bet with your money, manages the risk well* on most days*, and even if they lose your money you get it back anyway. FTX did the opposite of all that.
Chase is also more restricted in how the investment banking side of the business can use funds from the retail banking side, precisely because banks in the 1920s did play fast and loose with investing customer deposits, which caused a bunch of depositors to lose savings in the 1929 crash and associated bank runs.
So I think people don't like the comparison, since the true difference is FTX did horse betting, while Chase does something much more rational.